JP6938129B2 - Surface treatment liquid for wood, surface treatment liquid for molded boards, and their use - Google Patents

Description

Embodiments of the present invention relate to a surface treatment liquid for surface-treating a wood or a molded board, a surface-treated wood and a molded board, and a decorated wood and a molded board and a method for producing the same.

In recent years, it has been required to print various images on wood and molded boards used as building materials by using inkjet printing to enhance the aesthetic appearance. However, when inkjet printing is performed on a base material having voids on the surface such as wood and a molded plate, the ink permeates into the base material, so that there is a problem that the image quality is poor.

So far, a technique of applying an emulsion adhesive to the surface of wood before performing inkjet printing on wood (Patent Document 1), and an ink receiving layer containing a water-soluble polymer-based inkjet resin and a transparent filler. (Patent Document 2) is known. Further, there is also known a technique of providing a printing layer made of a cured product of an ultraviolet curable ink without forming an ink receiving layer on wood (Patent Document 3).

Japanese Patent No. 3701805 Japanese Unexamined Patent Publication No. 2008-93310 Japanese Unexamined Patent Publication No. 2012-111069

However, in the technique of Patent Document 1, since the adhesive closes the pores of the wood, it becomes difficult to maintain the hygroscopicity inherent in the wood. Further, according to the study by the present inventors, the image reproducibility is not sufficient with the technique of Patent Document 2 described above. Further, in the case of building materials and the like, the printed image is required to have scratch resistance in which scratches on the surface are not noticeable, but in the technique of Patent Document 3 above, scratches are easily noticeable and unnatural gloss is generated. Not only that, the original hygroscopicity of wood is also impaired.

Therefore, an object of the present invention is to provide a technique for forming an image having high quality and excellent scratch resistance on wood or a molded plate by inkjet printing.

According to one embodiment of the present invention, the cationic water-dispersible resin contains water, a cationic water-dispersible resin, and a surface tension modifier, and the cationic water-dispersible resin has a median diameter measured by a dynamic light scattering method. A surface treatment liquid for wood or molded plates containing large particles of 1 μm or more and 10 μm or less is provided.

According to another embodiment of the present invention, a surface treatment layer formed by using the surface treatment liquid of the above embodiment and containing the surface treatment liquid in a solid content of 0.5 g / m ^{2 or more is provided.} Surface-treated wood or surface-treated molded plates are provided.

According to another embodiment of the present invention, a surface treatment layer formed by using the surface treatment liquid of the above embodiment and containing the surface treatment liquid in a solid content of 0.5 g / m ² or more, and the surface treatment layer. A decorative wood or decorative molded plate is provided, which comprises an inkjet printing layer formed on the surface treatment layer.

According to still another embodiment of the present invention, there is a method for producing a decorative wood or a decorative molded plate using the surface treatment liquid of the above embodiment, wherein the surface treatment liquid for the wood or the molded plate is used as the wood or the molded plate. A step of applying to the surface to form a surface treatment layer containing the surface treatment liquid in an amount of 0.5 g / m ² or more in solid content, and inkjet printing using a water-based inkjet ink on the surface treatment layer. A method for producing a decorative wood or a decorative molded plate is provided, which includes a step of performing the above.

In the embodiment of the present invention, since a surface treatment liquid containing a specific cationic water-dispersible resin and a surface tension modifier is used, the surface of the base material (wood or molded plate) has excellent image quality and scratch resistance. A printed image can be formed.

Hereinafter, embodiments of the present invention will be described in detail, but it goes without saying that the present invention is not limited to these embodiments, and various modifications and changes may be made. Since "weight" and "mass" are used interchangeably in the present specification, they will be collectively referred to as "weight" below. In the following description, the surface treatment liquid for wood or molded board may be simply referred to as "surface treatment liquid" or "treatment liquid", and the inkjet ink may be simply referred to as "ink". Lumber and molded board may be collectively referred to as "base material".

<Surface treatment liquid for wood or molded board>
The surface treatment liquid according to the present embodiment is used for wood or molded boards, and contains at least water, a cationic water-dispersible resin, and a surface tension modifier. This surface treatment liquid is particularly preferably used as a pretreatment liquid before forming a printed image with an inkjet ink that is not a UV curable type. By using the surface treatment liquid of the present embodiment in advance before printing and then forming a printed image with inkjet ink, the quality of the printed image can be improved and scratches on the surface of the base material can be made inconspicuous.

In the present specification, "surface treatment" means to attach the surface treatment liquid to the base material by any means, and attaching the surface treatment liquid is also referred to as "coating" or "application". Further, the attachment portion may include not only the surface of the base material but also the inside (inner surface) of the voids of the base material.

[Cationic water-dispersible resin]
Inks generally contain components whose surface charge is anionic, and coloring materials such as pigments are also generally anionic. Therefore, by adhering the cationic component to the surface of the base material in advance using a surface treatment liquid containing the cationic component, an anion-cationic reaction occurs with the ink, and the ink component such as a coloring material is generated. Can be sufficiently suppressed from penetrating into the base material, and the coloring material can be retained on the surface of the base material.

The cationic component is preferably a water-dispersible resin and water-dispersible resin particles. Cationic water-dispersible resin particles are positively charged resin particles in which the surface of the resin particles is positively charged, and are dispersed in particles without being dissolved in water, and are oil in water (O / W). It is capable of forming mold emulsions. Like the self-emulsifying resin, the cationic functional group of the resin may be present on the particle surface, or the surface of the resin particle may be surface-treated such as by adhering a cationic dispersant.

Cationic functional groups are typically primary, secondary or tertiary amino groups, pyridine groups, imidazole groups, benzimidazole groups, triazole groups, benzotriazole groups, pyrazole groups, benzopyrazole groups and the like. The cationic dispersant is a primary, secondary, tertiary or quaternary amino group-containing acrylic polymer, polyethyleneimine, a cationic polyvinyl alcohol resin, a cationic water-soluble polybranched polyesteramide resin, and the like.

The amount of surface charge of the resin particles can be evaluated with a particle charge meter. The amount of surface charge can be calculated by measuring the amount of anions or cations required to neutralize the sample. Specifically, the amount of surface charge is preferably +300 μeq / g or more. As the particle charge meter, a colloid particle charge meter Model CAS manufactured by Nihon Rufuto Co., Ltd. can be used.

As the water-dispersible resin, it is preferable to use a resin that forms a transparent coating film. Further, in the production of the treatment liquid, it can be blended as an oil-in-water type resin emulsion.
Typically, ethylene-vinyl chloride copolymer resin, (meth) acrylic resin, styrene-maleic anhydride copolymer resin, urethane resin, vinyl acetate- (meth) acrylic copolymer resin, vinyl acetate-ethylene copolymer weight. Examples thereof include coalesced resins and resin emulsions thereof. Here, "(meth) acrylic resin" indicates both an acrylic resin and a methacrylic resin. These resins may be used alone or in combination of two or more. As will be described later, a resin emulsion in which these resins are combined may be used.
As described above, a cationic functional group can be introduced into these resins, or the surface can be surface-treated with a cationic dispersant or the like to give a positive surface charge.

The particle size of the resin particles is not particularly limited, and a plurality of types of particles having different particle sizes can be used in any combination. In one embodiment, the size of the median diameter (average particle size) measured by the dynamic light scattering method is 1 μm or more from the viewpoint of easily staying on the surface of the base material and easily fixing to the surface of the base material by heat drying or the like. It is preferable to include particles having. Further, the average particle size of the resin particles is preferably 10 μm or less, which allows the resin particles to penetrate into the recesses and voids on the surface of the base material while making the best use of the characteristics of the base material.

In a preferred embodiment, the cationic water-dispersible resin comprises large particles having a median diameter (average particle size) of 1 μm or more and 10 μm or less as measured by a dynamic light scattering method. As a result, the image quality and scratch resistance of the ink layer can be sufficiently ensured. That is, by using resin particles having a large particle size, a surface treatment layer is formed on a base material having surface irregularities and voids so as to follow the irregularities and voids without impairing the characteristics of the base material. This is considered to be because an ink layer having high scratch resistance and high image quality can be formed as a result. Further, in wood, by setting the median diameter (average particle size) to 1 μm or more and 10 μm or less, the surface treatment layer is efficiently formed according to the size of the voids (tubes described later in wood) existing in the base material. can do. In particular, for wood, the size of the pipe (average diameter) differs depending on the classification of softwood and hardwood. For example, the average diameter of the tamo lumber, which is a hardwood ring lumber, is about 260 μm, and the average diameter of the maple lumber, which is a perforated lumber, is about 60 μm. On the other hand, the average diameter of hinoki cypress, which is a coniferous tree, is about 10 μm. As described above, the size of the voids of wood differs depending on the tree species, and since it is a natural product, there is no wood in which the distribution of voids of the base material is exactly the same. By doing so, the surface treatment layer can be formed even on a base material having irregular voids such as wood without deteriorating the original function of the base material (hygroscopicity in wood).

In a more preferred embodiment, the surface treatment liquid also includes small particles having a median diameter (average particle size) of less than 1 μm measured by a dynamic light scattering method. Thereby, in addition to the above-mentioned image quality and scratch resistance, the water resistance of the ink layer can be further improved.

When using large particles and small particles, if the number of small particles is too small with respect to the large particles, the fixability is insufficient, and if the number of small particles is too large, the treated layer may be filmed and hinder the hygroscopicity of wood. Therefore, it is preferable that the number of small particles is about 0.1 to 1.5 with respect to 1 large particle in terms of weight ratio.

The average particle size of the resin particles is a volume-based particle size value (median diameter) in the particle size distribution measured by the dynamic light scattering method. As a dynamic light scattering type particle size distribution measuring device, a nanoparticle analyzer nano Partica SZ-100 (HORIBA, Ltd.) or the like is used, and water is used so that the concentration of the water-dispersible resin becomes 0.5% by mass. It can be diluted and measured at 25 ° C.

In the surface treatment liquid or the ink described later, the resin particles may be present in the state of independent fine particles or in the state of aggregates in which independent fine particles are aggregated. Dynamic light scattering The median diameter measured by the method is regarded as the "average particle size".
The average particle size of the resin particles is preferably measured in the state of the raw material emulsion before preparing the surface treatment liquid or the ink, because in the case of the ink, the influence of the coloring material (pigment particles) can be eliminated. The measured value can be used as the average particle size of the present embodiment.

The average particle size of the large particles is preferably 1 μm or more, preferably 10 μm or less, 7 μm or less, and 5 μm or less in this order. The average particle size of the small particles is preferably less than 1 μm and 500 nm or less in this order. The lower limit of the average particle size is not particularly limited, but from the viewpoint of storage stability of the surface treatment liquid, it is preferably about 5 nm or more, and more preferably 10 nm or more.

Further, it is preferable that the large particles and the small particles have two peaks in the particle size distribution when the average particle size is measured by mixing them, that is, each of them has a different peak value.

Further, the large particles and the small particles may have other differences in addition to the difference in the average particle size value. For example, large particles preferably have a minimum film forming temperature (MFT) of 70 ° C. or higher, while small particles preferably have an MFT of less than 70 ° C. This MFT is the temperature required for the emulsion to form a film (film formation), and can be measured according to JIS K6828-2. Here, the water-dispersible resin that does not form a film even at 70 ° C. is included in the water-dispersible resin having an MFT of 70 ° C. or higher.

More preferably, the MFT of the large particles is 100 ° C. or higher, the MFT of the small particles is 50 ° C. or lower, and in particular, the small particles are preferably formed at room temperature, so that the MFT is 40 ° C. or lower. ..
The difference between the MFT of large particles and the MFT of small particles is preferably 30 ° C. or higher, more preferably 50 ° C. or higher, and even more preferably 100 ° C. or higher.

The molecular structures of the large-particle and small-particle resins may be the same, but different ones may be used.
As the large particles, for example, a polymer having an anionic functional group represented by a carboxy group, a sulfo group or the like and a polymer having a cationic functional group represented by an amino group or an amide group are compounded and obtained. It is also preferable to use composite organic particles having a core-shell structure in which the core portion is an anionic polymer and the shell portion is a cationic polymer.

Examples of the anionic polymer of the composite organic particles include a polymer containing (meth) acrylic acid as a repeating unit, and more specifically, a styrene- (meth) acrylic acid copolymer. Other than styrene and (meth) acrylic acid, vinyl compounds copolymerizable with these may be contained.

The cationic polymer (basic polymer) of the composite organic particles is, for example, a polymer containing a nitrogen-containing monomer, and is a nitrogen heterocycle such as N-vinylpyrrolidone, N-vinylcaprolactam, N-vinyloxazolidone, and N-vinylimidazole. Examples include homopolymers or copolymers containing the compound as a repeating unit. As the comonomer forming the copolymer, for example, one or more general vinyl compounds such as styrene, (meth) acrylic acid ester, vinyl acetate, and acrylamide can be selected and used.

In this case, the ratio of the anionic polymer to the cationic polymer used is preferably 3 to 10 in terms of weight ratio of the cationic polymer to 1 in order to make the charge on the particle surface cationic. ..
As commercially available products of such composite organic particles, "PP-15" and "PP-17" (both from Meisei Chemical Works, Ltd.) can be preferably used.

The amount of the water-dispersible resin in the surface treatment liquid (the total solid content of both large particles and small particles when used) is 2% by weight or more from the viewpoint of ink fixability on the surface of the base material when treated. It is preferably 3% by weight or more, and even more preferably 5% by weight or more. On the other hand, if the viscosity of the treatment liquid is too high, uniform treatment becomes difficult, so the amount of resin is preferably 50% by weight or less, and more preferably 30% by weight or less.

[solvent]
The water functions as a solvent for the treatment liquid, that is, a vehicle, and tap water, ion-exchanged water, deionized water, and the like can be used. Water is a highly volatile solvent and easily evaporates after being discharged to the base material. Therefore, it is possible to prevent the voids of the base material after the surface treatment from being closed, and after the surface treatment such as moisture absorption of wood. It acts to prevent deterioration of the original characteristics of the base material. In addition, water is harmless, highly safe, and does not have problems such as VOC, so that the surface-treated base material can be made environmentally friendly.

The higher the content of water in the surface treatment liquid, the lower the viscosity of the surface treatment liquid and the easier it is to handle. Therefore, the water content is preferably 60% by weight or more, preferably 65% by weight or more, based on the total amount of the treatment liquid. Is more preferable.
The upper limit of the water content is not particularly limited, but in one embodiment containing large particles and small particles of the water-dispersible resin in the treatment liquid, the water content is preferably 95% by weight or less. , 90% by weight or less is more preferable. In another embodiment, the water content is preferably 85% to 95% by weight.

The solvent of the treatment liquid is preferably composed mostly of water, but may contain a water-soluble organic solvent in addition to water, if necessary. As the water-soluble organic solvent, an organic compound that is liquid at room temperature and is soluble in water can be used, and it is preferable to use a water-soluble organic solvent that is uniformly mixed with the same volume of water at 1 atm and 20 ° C. ..

For example, lower alcohols such as methanol, ethanol, 1-propanol, isopropanol, 1-butanol, 2-butanol, isobutanol, 2-methyl-2-propanol; ethylene glycol, diethylene glycol, triethylene glycol, tetraethylene glycol, polyethylene. Glycols such as glycol, propylene glycol, dipropylene glycol, tripropylene glycol, polypropylene glycol; glycerins such as glycerin, diglycerin, triglycerin, polyglycerin; acetylines such as monoacetin, diacetin, triacetin; ethylene glycol monomethyl ether, Ethylene glycol monoethyl ether, ethylene glycol monopropyl ether, ethylene glycol monobutyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol monopropyl ether, diethylene glycol monobutyl ether, triethylene glycol monomethyl ether, triethylene glycol monoethyl ether, triethylene Glycol ethers such as glycol monopropyl ether, triethylene glycol monobutyl ether, tetraethylene glycol monomethyl ether, tetraethylene glycol monoethyl ether, tetraethylene glycol dimethyl ether, tetraethylene glycol diethyl ether; triethanolamine, 1-methyl-2- Pyrrolidone, 1,3-dimethyl-2-imidazolidinone, β-thiodiglycol, sulfolane and the like can be used. The boiling point of the water-soluble organic solvent is preferably 100 ° C. or higher, more preferably 150 ° C. or higher.

These water-soluble organic solvents may be used alone, or may be used in combination of two or more as long as they form a single phase with water. The content of the water-soluble organic solvent is preferably 30% by weight or less (or 50% by weight or less in the solvent) in the treatment liquid from the viewpoint of viscosity adjustment and moisturizing effect.

[Surface tension adjuster]
The surface treatment liquid reduces its surface tension so that it can be uniformly applied to the surface of the base material, and when it contains water-dispersible resin particles (small particles) having a small particle size, it suppresses their aggregation. Therefore, it is preferable to further contain a surface tension adjusting agent (surfactant) in order to improve the storage stability of the liquid.

Surfactants are roughly classified into those having an ionic (cationic / anionic / dichotomous) hydrophilic portion and those having a nonionic (nonionic) hydrophilic portion. From the viewpoint, it is preferable to use a non-ionic surfactant that does not easily foam. Further, either a small molecule system or a polymer system (generally, a substance having a molecular weight of about 2000 or more) may be used, but it is preferable to use a polymer system surfactant.
The HLB value is preferably about 5 to 20 surfactants.

Examples of the nonionic surfactant include ester-type surfactants such as glycerin fatty acid ester and fatty acid sorbitan ester, and ether-type surfactants such as polyoxyethylene alkyl ether, polyoxyethylene alkyl phenyl ether, and polyoxypropylene alkyl ether. , Ether ester type such as polyoxyethylene sorbitan fatty acid ester and the like.

In this embodiment, an acetylene glycol-based surfactant and a silicone-based surfactant can be preferably used.
Commercially available products of acetylene glycol-based surfactants include acetylene glycols, surfinol 104E and 104H, acetylene glycol with ethylene oxide added, surfinol 420, 440, 465, 485, etc. (Air Products & Chemicals), acetylene. Glycol Orphine E-1004, E-1010, E-1020, PD-002W, PD-004, EXP. 4001, EXP-4200, EXP-4123, EXP-4300, etc. (Nissin Chemical Industry Co., Ltd.), acetylenol E00, E00P of acetylene glycol, acetylenol E40, E100, etc. with a structure to which ethylene oxide of acetylene glycol is added (Kawaken Fine Chemicals) Co., Ltd.).

Since the silicone-based surfactant has a very high surface tension lowering ability and contact angle lowering ability, the treatment liquid can be rapidly diffused on the base material surface even if the base material surface is not hydrophilic. As a result, the functional expression component of the treatment liquid can be uniformly fixed on the surface of the base material, so that the ink is uniformly fixed on the treatment portion at the time of printing, and a high-colored and high-quality printed image can be obtained. can.
Among the silicone-based surfactants, a polyether-modified silicone-based surfactant, an alkyl-aralkyl co-modified silicone-based surfactant, and an acrylic silicone-based surfactant are preferable. As a commercially available product, "Silface SAG series" (Nisshin Kagaku Kogyo Co., Ltd.) can be preferably used.

As the surfactant, the above-mentioned silicone-based surfactant or the like may be used alone, or a plurality of surfactants having good compatibility with each other may be used in combination.
When a surfactant is used, the content in the surface treatment liquid is preferably about 0.1% by weight or more, more preferably 0.3% by weight or more, and more preferably 0.5% by weight or more. On the other hand, the amount of the surfactant is preferably about 5% by weight or less, more preferably 4% by weight or less, and further preferably 3% by weight or less.

[Other ingredients]
In addition to the above components, known additives such as moisturizers, antifoaming agents, pH adjusters, antioxidants, and preservatives can be optionally added to the treatment liquid as long as the functions of the treatment liquid are not impaired. .. A plurality of types of these additives may be used in combination.

The treatment liquid includes water, a cationic water-dispersible resin, a surface tension modifier, and any additives that are optionally added, and all the components are collectively or all of the components are put into a known disperser such as a bead mill. It can be prepared by dividing, charging, dispersing, and if desired, passing through a known filter such as a membrane filter.

[wood]
The wood as the base material means a wooden board cut out from a natural tree, a thinly sliced veneer (veneer), and a plywood (structural plywood, etc.) obtained by laminating and thermocompression-bonding the veneer. The type of tree, the method of producing plywood, the number of laminated trees, and the like are not particularly limited. The thickness of the wood is not particularly limited, and it can be widely used from a thin veneer of about 0.1 mm to a thick solid board of about several centimeters.

Wood has pipes (conduit) that have the role of passing water. Wood is broadly classified into conifers and hardwoods. Conifers have temporary conduits, hardwoods have conduits, and depending on the species, conifers also have temporary conduits and resin paths through which secreted tar (resin) passes. do. In broad-leaved trees, ring-hole lumbers (oak wood, tamo wood, zelkova wood, etc.) in which conduits are arranged in a ring shape and holes are formed in a ring shape, and perforated materials (maple wood) in which the conduits are not arranged and are dispersed throughout. Lumber, maple lumber, walnut lumber, cherry lumber, etc.) Depending on how these conduits are distributed, a grain pattern appears on the surface of the wood.

On the surface of wood processed into a plate shape, the inside of the conduit is exposed, and when printing is performed on the surface with water-based ink, bleeding occurs along the conduit and the fine line reproducibility is deteriorated. On the other hand, by performing the surface treatment with the surface treatment liquid of the present embodiment, the cationic water-dispersible resin in the surface treatment liquid controls the wetting and spreading of the ink inside the conduit, and it is difficult to bleed and the fine line reproducibility is good. Moreover, it is possible to form a printed image having good color development. Further, when the surface treatment layer penetrates into the inside of the conduit, the printed layer is sufficiently fixed inside the conduit, and as a result, scratches on the surface can be made inconspicuous.

Further, since the surface treatment liquid of the present embodiment contains the above-mentioned components, it is necessary to suppress a decrease in hygroscopicity inherent in wood and to form a surface treatment layer and a printing layer while maintaining the hygroscopic performance of wood. Can be done.

[Molded plate]
A typical example of the molded board (molded board) is a wood board (or fiber board), but a molded board using a raw material other than wood, for example, a plant-derived material other than wood can also be preferably used. In the present embodiment, it is preferable that the molded plate (plant-derived molded plate) is mainly made of a plant-derived product (wood or a plant other than wood).

Examples of the wood board include an insulation board, a particle board, an MDF (medium density fiber board), and a hard board. These are small pieces, powder, or fibrous materials (wood chips, crushed bark chips, wood flakes, oga powder, etc.) of various unused wood materials (forest waste materials, small-diameter wood, plywood factory waste materials, building dismantling materials, etc.). , Wood wafers, wood strands, etc.), and is obtained by compression molding by a dry method or a wet method. Examples of commercially available products include "Renowood" (Takemura Industry Co., Ltd.) using cypress.

Examples of plant-derived materials other than wood include straw, rice husk, rush, and pieces of vegetation, such as "Harvest Panel" (Takaoka Kenzai Co., Ltd.), "Momigara Eco Board" (Kovalin Co., Ltd.), " Commercially available products such as "Igusa board" (Swood Co., Ltd.) can be used.

Since the surface of the molded plate using a plant-derived product is hydrophilic, the water-based ink spreads and bleeds. However, by using the surface treatment liquid of the present embodiment in advance, bleeding occurs as in the case of the above-mentioned wood. Since it is difficult and the fine line reproducibility is good, the color development is good, and the ink can be adhered well to the unevenness and voids of the molded plate, it is possible to form a printed image in which scratches are not conspicuous.

<Surface-treated wood or surface-treated molded board>
The surface-treated wood or molded board is a wood or molded board that has been surface-treated with the surface-treating liquid of the above embodiment, and includes a surface-treated layer. The surface treatment layer preferably contains a surface treatment liquid having a solid content of 0.5 g / m ^{2 or more.} That is, this surface treatment layer is a layer containing a cationic water-dispersible resin and a surface tension adjusting agent, and when the surface treatment liquid contains non-volatile components other than these, the surface treatment layer also contains those non-volatile components. ..
The surface treatment layer may be present on at least a part of the surface of the wood or the molded plate, but may be formed on the entire surface.

When the surface treatment layer contains a surface treatment liquid having a solid content of 0.5 g / m ² or more, the effect of preventing ink bleeding is exhibited, and the ^{surface treatment layer contains a surface treatment liquid having a solid content of 1 g / m 2} or more. It is more preferable, and it is more preferable to contain a surface treatment liquid having a solid content of 1.5 g / m ^{2 or more.} On the other hand, the upper limit of the surface treatment liquid of the surface treatment layer is not particularly limited, but from the viewpoint of water resistance of the image, if the surface treatment liquid is too large, the surface treatment liquid that cannot completely penetrate into the base material dries and the surface. The treatment layer is formed thick, and after decoration, the surface treatment layer dissolves due to the adhesion of moisture, and the entire decoration portion may be peeled off, which may reduce the water-scratch resistance of the decoration product. Therefore, the solid content is 10 g / m. It may be preferably ^{2 or less.} From the viewpoint of water scratch resistance, the amount of the surface treatment liquid ^{is more preferably 7 g / m 2} or less in terms of solid content, and further preferably 5 g / m ² or less and 4 g / m ² or less in this order.

In one preferred embodiment, the surface-treated layer comprises cationic water-dispersible resin particles having a median diameter of 1 μm or more and 10 μm or less, and in a more preferred embodiment, the surface-treated layer has a median diameter of 1 μm or more and 10 μm or more. It contains both the following cationic water-dispersible resin particles and cationic water-dispersible resin particles having a median diameter of less than 1 μm.

The wood and the molded board may be subjected to an arbitrary base coating, hydrophilic treatment, or the like before the surface treatment. In that case, the coating is preferably carried out with a water-based paint. In addition, it is necessary to apply a base coating that does not reduce the hygroscopicity inherent in wood and molded boards.

<Manufacturing method of surface-treated wood or surface-treated molded board>
For surface-treated wood or surface-treated molded board, a surface-treated liquid for wood or molded board is applied to the surface of the wood to form a surface-treated layer containing the surface-treated ^{liquid in a solid content of 0.5 g / m 2 or more.} It can be preferably produced by a method for producing a surface-treated wood or a surface-treated molded plate including the step of performing.

The surface treatment liquid may be applied or adhered to the surface of the substrate by uniformly applying the surface treatment liquid to the surface of the substrate using a brush, a roller, a bar coater, an air knife coater, or a spray, or inkjet printing. , Gravure printing, flexographic printing, or other printing means may be used to print the image. That is, the surface treatment liquid may be applied to the entire surface of the base material surface, or may be applied only to necessary places, for example, only to places where inkjet printing is performed.

When the surface treatment liquid contains large particles and small particles as the cationic water-dispersible resin, the application of the surface treatment liquid can be performed in two steps. That is, for example, a surface treatment liquid containing either large particles or small particles and a surface treatment liquid containing the other one can be prepared and both can be applied to the base material. When applying the large particles and the small particles separately, if the small particles are applied first, the penetration into the voids of the base material may proceed and the effect as a binder for the ink may be diminished. Therefore, the large particles are applied first. It is preferable to apply to.

It is preferable that the surface treatment liquid is adhered to the base material, dried, and then inkjet printing is performed. At that time, it is preferable to shorten the drying time by heating and drying, but it may be preferable not to heat depending on the type of the base material. For example, it is preferable to dry the veneer at room temperature without heat-drying in order to avoid bending of the veneer due to heating.
On the other hand, it is also possible to perform inkjet printing immediately after the surface treatment liquid is adhered to the substrate, that is, without drying the surface treatment liquid.

<Decorative wood or decorative molded board>
The decorative wood or decorative molded plate is formed by using the surface treatment liquid of the above embodiment, and includes a surface treatment layer containing the surface treatment ^{liquid in an amount of 0.5 g / m 2 or more in terms of solid content, and the surface thereof.} A wood or molded plate comprising an inkjet printing layer formed on the treated layer. In the present specification, "decoration" is synonymous with decoration and means forming a printed image, and "decorated" means having a printed image (printing layer or ink layer). means. This printing layer may be the entire surface or a part of the base material. The base material before printing may be one that has been subjected to any other treatment after the surface treatment with the above treatment liquid.

The decorative wood or decorative molded plate includes a printing layer by on-demand printing using inkjet ink. In addition, since printing can be performed on the base material without giving an unnatural luster or the like by decoration and without impairing the properties peculiar to the base material such as wood, it bleeds with high color while making the best use of the natural appearance of the base material. Has an image without.

[Inkjet ink]
The ink for performing inkjet (IJ) printing on the surface-treated wood or the surface-treated molded plate is not particularly limited as long as it is an IJ ink, but it is preferably an ink that is not UV-curable, and is a water-based ink. Is preferable. That is, it is preferable that the IJ ink contains water, a binder resin, and a coloring material.

The water is not particularly limited as long as it functions as an ink solvent, that is, a vehicle, and tap water, ion-exchanged water, deionized water, and the like can be used. As described above for the surface treatment liquid, since water is safe and highly volatile, it is possible to prevent deterioration of the original performance of the decorated base material.

The content of water in the ink is preferably 30% by weight or more, more preferably 60% by weight or more, and further preferably 65% by weight or more of the total amount of ink. The water content is preferably 95% by weight or less, more preferably 90% by weight or less.

The solvent of the ink is preferably composed mostly of water, but may contain a water-soluble organic solvent in addition to water, if necessary. As the water-soluble organic solvent, one or two or more kinds of solvents similar to those that can be used for the surface treatment liquid can be selected and used.
When two or more kinds of water-soluble organic solvents are used, the total content thereof is preferably 5 to 50% by mass, more preferably 10 to 35% by mass.

As the binder resin, a water-soluble resin or a hydrophilic resin can be used, and is not particularly limited. In order to improve the water resistance of the obtained image, it is preferable to contain a water-dispersible resin, and the water-dispersible resin may be used in combination with the water-soluble resin.

Examples of the water-soluble resin include polyvinyl alcohol, polyacrylic acid, neutralized polyacrylic acid, acrylic acid / maleic acid copolymer, acrylic acid / sulfonic acid copolymer, styrene / maleic acid copolymer and the like. These can be used alone or in combination of two or more.

In the case of a water-dispersible resin, it is preferable to use anionic resin particles having a negatively charged particle surface and a negative charge. This is capable of forming an oil-in-water (O / W) type emulsion by dispersing in particles without being dissolved in water. Like the self-emulsifying resin, the anionic functional group of the resin may be present on the particle surface, or the surface of the resin particle may be surface-treated such as attaching an anionic dispersant. The anionic functional group is typically a carboxy group, a sulfo group or the like, and the anionic dispersant is an anionic surfactant or the like. When the surface is anionic, a chemical interaction with the cationic water-dispersible resin in the surface treatment liquid is obtained, and as a result, the fixing of the coloring material is further strengthened and the durability of the image is further improved. Can be enhanced.
The surface charge of the resin particles can be evaluated by measuring the zeta potential. Specifically, the absolute value of the zeta potential is preferably 30 mV or more.

As the type of resin, it is preferable to use a resin that forms a transparent coating film. In addition, it can be blended as a resin emulsion in the production of ink.
Typically, ethylene-vinyl chloride copolymer resin, (meth) acrylic resin, styrene-maleic anhydride copolymer resin, urethane resin, vinyl acetate- (meth) acrylic copolymer resin, vinyl acetate-ethylene copolymer resin. Examples thereof include coalesced resins and resin emulsions thereof, which can be used alone or in combination of two or more. Here, "(meth) acrylic resin" indicates both an acrylic resin and a methacrylic resin.
As described above, an anionic functional group can be introduced into these resins, or the surface can be surface-treated with an anionic dispersant or the like to give a negative surface charge.

Among these water-dispersible resins (or emulsions thereof), urethane resins having a glass transition temperature (Tg) of 35 to 40 ° C. from the viewpoint of stable ejection performance from an inkjet head and adhesion to a substrate (Tg). Emulsion) is preferably used. Specific examples of such resin emulsions include Superflex 460, 420, 470, 460S (carbonate-based urethane resin emulsions, all of which are trade names) and 150HS (ester / ether-based urethane resin emulsions / products) of Daiichi Kogyo Seiyaku Co., Ltd. Name), 740, 840 (aromatic isocyanate-based ester-based urethane resin emulsion, all trade names), DSM NeoRez R-9660, R-2170 (aliphatic polyester-based urethane resin emulsion, all trade names), NeoRez Examples thereof include R-966, R-967, R-650 (polyurethane polyether urethane resin emulsion, all trade names), R-986, R-9603 (polyurethane polycarbonate, all trade names) and the like.

Further, from the viewpoint of stability in ink, it is also preferable to use a (meth) acrylic resin or a (meth) acrylic resin copolymer. Specifically, Movinyl 966A, 6963, 6960 (acrylic resin emulsion, all trade names), 6696D, RA-033A4 (styrene / acrylic resin emulsion, all trade names) and BASF of Nippon Synthetic Chemical Industry Co., Ltd. John Krill 7100, PDX-7370, PDX-7341 (styrene / acrylic resin emulsion, all trade names), DIC Co., Ltd. Boncoat EC-905EF, 5400EF, CG-8400 (acrylic / styrene emulsion), etc. Can be mentioned.
The water-dispersible resin may be composed of a single resin (or an emulsion thereof) such as a urethane resin or an acrylic resin, or may be composed of a combination of a plurality of resins (or emulsions thereof). good.

The water-dispersible resin particles forming the emulsion may have a particle size suitable for inkjet printing, and generally have an average particle size (medium diameter measured by a dynamic light scattering method on a volume basis) of 300 nm or less. It is preferably 250 nm or less, more preferably 200 nm or less, and even more preferably 150 nm or less. The lower limit of the average particle size is not particularly limited, but from the viewpoint of storage stability of the ink, it is preferably about 5 nm or more, and more preferably 10 nm or more.

The amount (solid content) of the water-dispersible resin and / or the water-soluble resin in the ink is preferably 1: 0.5 to 1: 7 (weight ratio) in terms of the ratio of the coloring material to the resin (coloring material: resin). By setting the resin content in this range, it is possible to sufficiently ensure the water scratch resistance and high image quality of the image printed on the surface of the base material. If the ratio of the resin to the color material 1 is less than 0.5, the fixability of the pigment may be deteriorated, and if it is larger than 7, the viscosity may be high and the ink may not be ejected from the head that ejects the ink. There is.

As the color material of the ink, either a pigment or a dye can be used, and both may be used alone or in combination. From the viewpoint of weather resistance and print density of the decorative image, it is preferable to use a pigment as a coloring material.
The content of the coloring material is preferably in the range of 0.01 to 20% by weight with respect to the total amount of ink. Further, the content of the coloring material is more preferably 0.1% by weight or more, further preferably 0.5% by weight or more, further preferably 1% by weight or more, and 15% by weight. % Or less, more preferably 10% by weight or less, and even more preferably 8% by weight or less.

As the dye, a dye generally used in the technical field of printing can be used, and the dye is not particularly limited. Specific examples thereof include basic dyes, acid dyes, direct dyes, soluble bat dyes, acid medium dyes, medium dyes, reactive dyes, bat dyes, sulfide dyes, etc. Among these, water-soluble dyes, reduction dyes, etc. Those that become more water-soluble can be used. More specifically, azo dyes, rhodamine dyes, methine dyes, azomethine dyes, xanthene dyes, quinone dyes, triphenylmethane dyes, diphenylmethane dyes, methylene blue and the like can be mentioned. These dyes may be used alone or in combination of two or more.

As the pigment, organic pigments such as azo pigments, phthalocyanine pigments, polycyclic pigments and dyed lake pigments, and inorganic pigments can be used. Examples of the azo pigment include soluble azo lake pigments, insoluble azo pigments and condensed azo pigments. Examples of the phthalocyanine pigment include metal phthalocyanine pigments and non-metal phthalocyanine pigments. Polycyclic pigments include quinacridone pigments, perylene pigments, perinone pigments, isoindolin pigments, isoindolinone pigments, dioxysazine pigments, thioindigo pigments, anthracinone pigments, quinophthalone pigments, and metal complex pigments. And diketopyrrolopyrrole (DPP) and the like. Typical examples of the inorganic pigment include carbon black and titanium oxide. These pigments may be used alone or in combination of two or more.

A pigment dispersant can be added to the ink, if necessary, in order to improve the dispersion of the pigment in the ink. The pigment dispersant that can be used is not particularly limited as long as it stably disperses the pigment in the solvent, and is, for example, a known pigment represented by a polymer dispersant or a surfactant having a pigment-dispersing ability. It is preferable to use a dispersant. Specific examples of the polymer dispersant include Solspers (trade name) series manufactured by Nippon Lubrizol Co., Ltd., John Krill (trade name) series manufactured by Johnson Polymer Co., Ltd., DISPERBYK series manufactured by BYK, and BYK series. .. Specific examples of surfactants include nonionic polys such as anionic fatty acid salts, alkyl sulfates, alkyl ether sulfates, and alkylbenzene sulfonates, such as the Demol (trade name) series manufactured by Kao Co., Ltd. Examples thereof include oxyalkylene alkyl ethers.
The content of the pigment dispersant is sufficient as long as the pigment can be sufficiently dispersed in the solvent, and can be appropriately set, for example, in the range of 0.01 to 2 by weight with respect to the pigment 1.

In addition, a surface tension lowering agent (surfactant) is used to reduce the surface tension of the ink in the ink, ensure ejection stability when introduced into the inkjet head, and allow the ink to quickly penetrate into the substrate to be printed. Agent) can be added. As the surface tension lowering agent, a surfactant having an effect of further suppressing the aggregation of water-dispersible resin particles, for example, a surfactant similar to that blended in the surface treatment liquid can also be used. A surfactant having both a pigment dispersion function and a surface tension lowering function may be used.
The amount of the surface tension lowering agent in the ink is preferably about 0.1% by weight or more, more preferably 0.3% by weight or more, and even more preferably 0.5% by weight or more. On the other hand, the amount of the surface tension lowering agent is preferably about 5% by weight or less, more preferably 4% by weight or less, and even more preferably 3% by weight or less.

In addition to the above components, other components such as a moisturizer, an antifoaming agent, a pH adjuster, an antioxidant, and a preservative can be added to the ink as long as the properties of the ink are not adversely affected.

The method for producing the ink is not particularly limited, and the ink can be appropriately produced by a known method. For example, all the components can be collectively or divided and dispersed in a known disperser such as a bead mill, and if desired, can be prepared by passing through a known filter such as a membrane filter. For example, a mixed solution in which the entire amount of water and the coloring material is uniformly mixed is prepared in advance, dispersed by a disperser, and then the remaining components are added to the dispersant and passed through a filter to prepare the mixture. Can be done.

<Manufacturing method of decorative wood or decorative molded board>
The decorative wood or decorative molded plate is a surface obtained by applying the surface treatment liquid for wood or molded plate to the surface of wood or molded plate and containing the surface treatment liquid in a solid content of 0.5 g / m ² or more. It can be preferably produced by a method for producing a decorative wood or a decorative molded plate, which comprises a step of forming a treated layer and a step of performing inkjet printing using a water-based inkjet ink on the surface treated layer. It is not limited to this. The method for forming the surface-treated layer is as described in the method for producing the surface-treated wood or the surface-treated molded plate.

[Inkjet printing]
Inkjet printing using water-based ink on surface-treated wood or surface-treated molded board can be performed using a general recording head, and there are no particular restrictions on the printing method, the equipment used, or the like. After printing (decoration), by drying, water and other volatile components are volatilized from the printed ink, and an image mainly composed of binder resin and coloring material is displayed on the surface of wood or molded board. A decorative wood or decorative molded plate is obtained.
The recording area of the image is not particularly limited, and any pattern or character, or a combination of the pattern and the character can be freely selected.

In order to obtain a higher quality decorative image, (i) reduce the ink droplets, (ii) slow down the printing speed, (iii) perform unidirectional printing, (iv) print while warming the substrate, It is effective to use printing conditions such as (v) lowering the printing resolution or (vi) printing in combination of these methods.

In particular, the above printing conditions for printing while warming the base material are such that when it is necessary to obtain a highly colored image with a small amount of ink, the base material has many irregularities or a plurality of base materials having different ink water absorption performances. It is also effective as a printing condition when the straddling pattern is printed uniformly. By printing while warming the base material, it is possible to form the presence position of pigments, which are components other than water in the ink, near the surface of the base material, which affects the shape and properties of the base material. It becomes smaller and it becomes possible to obtain a stable image.

The base material may be heated after the printing is completed, water and other volatile components in the ink may be completely volatilized, and the coloring material in the ink may be fixed to the base material by the binder resin.
The method for heating the base material is arbitrary, and the heating temperature is not particularly limited as long as the nozzle used for inkjet printing is dry and the ejection is not unstable, and can be heated in the range of, for example, 50 to 100 ° C.

The device for decorating is not particularly limited, but for example, a mounting portion for mounting the base material, a surface treatment liquid coating portion for applying the surface treatment liquid to the surface of the base material, and the like. A decorating device can be used that includes at least an inkjet recording head arranged for ejecting ink and performing inkjet printing, and more preferably an optional heating unit for heating the substrate.

More specifically, the decorating device is water-based on the surface of an input unit (for example, a scanner) for providing electronic data (having a pixel value corresponding to each pixel) of an image to be decorated, and a surface of a base material. The recording head unit that ejects ink to record an image, the transport unit that transports the base material to a position facing the discharge nozzle formed on the lower surface of the recording head unit with the base material placed, and the base material A surface treatment liquid application portion for applying the surface treatment liquid to the surface of the recording head portion can be provided before reaching the recording head portion. Further, a heating unit (various heaters such as a ceramic heater) for heating the decorative area on the substrate can be provided at any stage during printing or before and after printing to promote the drying of the discharged treatment liquid and / or ink. It is preferable to do so.

Hereinafter, the present invention will be described in more detail based on Examples, but the present invention is not limited to these Examples. Unless otherwise specified, "%" is "% by weight". The blending amount of each component in the table is also indicated by "% by weight".

<Preparation of surface treatment liquid>
Each component listed in Table 1 was premixed at the ratio shown in Table 1 and then dispersed with a homogenizer for 1 minute to obtain surface treatment liquids 1 to 11.

Details of the raw materials listed in Table 1 are as follows. The calcium chloride aqueous solution is an aqueous solution prepared by dissolving calcium chloride manufactured by Wako Pure Chemical Industries, Ltd. in water and adjusting the concentration to 50%. Glycerin is a special grade reagent manufactured by Wako Pure Chemical Industries.
"PP-15": Cationic water-dispersible composite organic particles manufactured by Meisei Chemical Industry Co., Ltd. (average particle size of about 1.8 μm, no film formation at 100 ° C.)
"PP-17": Cationic water-dispersible composite organic particles manufactured by Meisei Chemical Industry Co., Ltd. (average particle size of about 2.5 μm, no film formation at 100 ° C)
"Polysol AE-803": Showa Denko KK, cationic water-based acrylic resin emulsion (average particle size 419 nm, MFT 0 ° C)
"Polysol AP-1370": Showa Denko KK, cationic water-based acrylic resin emulsion (average particle size 206 nm, MFT 10 ° C)
"Pascol JK-870": Cationic water-based urethane resin emulsion manufactured by Meisei Kagaku Kogyo Co., Ltd. (average particle size 50 nm)
"Viniblanc 271": Anionic vinyl chloride emulsion (average particle size 230 nm) manufactured by Nisshin Kagaku Kogyo Co., Ltd.
"MP-2040": Nissan Chemical Industries, Ltd., silica sol (average particle size 200 nm)
"Snowtex 20L": Colloidal silica manufactured by Nissan Chemical Industries, Ltd. (average particle size 40 to 50 nm)
"Snowtex 30": Colloidal silica manufactured by Nissan Chemical Industries, Ltd. (average particle size 10 to 15 nm)
"Viniblanc 1035F": Vinyl acetate emulsion resin manufactured by Nissin Chemical Industry Co., Ltd. (non-ionic water-dispersible resin, average particle size 1000 nm (reference value))
"Eslek KX-3": Sekisui Chemical Co., Ltd., polyvinyl acetal resin "Silface SAG503A": Nissin Chemical Industry Co., Ltd., silicone-based surfactant "Orfin E1010": Nissin Chemical Industry Co., Ltd. Made by acetylene glycol-based surfactant

The average particle size of the resin is determined by using a dynamic light scattering type particle size distribution measuring device "nano particle analyzer nano-Prtica SZ-100" (manufactured by Horiba Seisakusho Co., Ltd.) to obtain a particle concentration of 0.5 mass for each resin dispersion. It was diluted with purified water so as to be%, and the dispersion medium refractive index was set to 1.333, the sample refractive index was set to 1.600, the dispersion form was set to "multidisperse" and "narrow", and the measurement was performed at a temperature of 25 ° C. Volume-based median diameter.

<Preparation of water-based ink set>
Each component shown in Table 2 was premixed at the ratio shown in Table 2, and the obtained dispersion was passed through a membrane filter having a pore size of 3 μm to obtain 6 colors (cyan, magenta, yellow, black, light cyan, light magenta). Aqueous ink sets 1 to 3 comprising the above were obtained.

The details of the raw materials shown in Table 2 are as follows (excluding the same raw materials as those shown in Table 1).
"CAB-O-JET 250C": Cabot, water-based self-dispersed cyanide pigment dispersion "CAB-O-JET 260M": Cabot, water-based self-dispersed magenta pigment dispersion "CAB-O-JET 270Y": Cabot Water-based self-dispersed yellow pigment dispersion "BONJET BLACK CW-4": Orient Chemical Industry Co., Ltd., Water-based self-dispersed carbon black dispersion "Superflex 470": Daiichi Kogyo Seiyaku Co., Ltd., anionic Water-based urethane resin emulsion (average particle size 83 nm)
"Kuraray Poval PVA205": Partially saponified polyvinyl alcohol manufactured by Kuraray Co., Ltd. (saponification degree 86.5-89 mol%)
"Surfinol 465": Acetylene glycol-based surfactant manufactured by Nissin Chemical Industry Co., Ltd.

<Manufacturing of surface-treated wood and surface-treated molded board>
As shown in Tables 3-1 and 3-2, and Table 3-3 (hereinafter collectively referred to as "Table 3"), each surface treatment liquid is applied to the entire surface of wood or molded board using an electric spray. It was worked and left overnight at 23 ° C. and 50% relative humidity. The amount of the surface treatment liquid applied is as shown in Table 3.

The base materials used are as follows.
Wood 1: Hard maple (wide-leaved tree, perforated material), thickness 0.6 mm, veneer Wood 2: Veneer (coniferous tree), thickness 0.2 mm, veneer Wood 3: Hinoki (coniferous tree), thickness 10 mm, veneer Wood 4: Tamo (Hyperwood, veneer), thickness 0.6 mm, veneer wood 5: spruce (conifer), thickness 0.6 mm, veneer molded plate 1: "Harvest Panel" (straw) made by Takaoka Kenzai Co., Ltd., thickness 18 mm
Molded plate 2: "Lenowood" (cypress) manufactured by Takemura Industry Co., Ltd., thickness 17 mm
Molded plate 3: "Momigara eco board" (rice husk) made by Kovalin Co., Ltd., thickness 14 mm
Molded plate 4: "Igusa board" (rush) made by Eswood Co., Ltd., thickness 8 mm

<Evaluation of surface-treated products>
The obtained surface-treated products (surface-treated wood, surface-treated molded plate) were evaluated as follows. The evaluation criteria are as shown in Table 4.
Substrate surface property: With respect to the surface-treated substrate, it was visually determined whether the surface pattern of the substrate remained with the same texture as the unsurface-treated substrate.

<Manufacturing of decorative wood and decorative molded boards>
With respect to the surface-treated products (Comparative Examples 1 and 11 are unsurface-treated products) of Examples and Comparative Examples (excluding Comparative Example 4), each ink set shown in Table 2 was used for each color of a commercially available water-based pigment inkjet printer. Inkjet prints a solid image, a 0.3 mm fine line image, a wood grain image for wood, and a gradation image for a molded plate, and heat them at 80 ° C for 10 minutes. The printed surface was dried. In Comparative Example 4, Roland Dee. Gee. Using ECO-UV ink for VersaUV LEF-12, a UV printer manufactured by the company, each image is printed on unsurface-treated wood 1 using the same printer, and then UV-cured with the UV-LED lamp built into the printer. rice field.

<Evaluation of decorative items>
The obtained decorative products (decorative wood, decorative molded plate) were evaluated as follows. The evaluation criteria are as shown in Table 4.
Image quality 1 (glossiness): The glossiness of the printed wood grain image or gradation image was visually determined.
Image quality 2 (reproducibility of wood grain image): The reproducibility of the printed wood grain image was visually determined with respect to the decorative wood.
Image quality 3 (reproducibility of gradation image): The reproducibility of the printed full-color gradation image was visually determined for the decorative molded product.
Image quality 4 (color development): The color development of the printed solid image was visually determined. A solid image was also printed on inkjet paper, and it was evaluated whether or not it had the same color development.
Image quality 5 (fine line reproducibility): The degree of bleeding, blurring, and sharpness of the printed 0.3 mm fine line was visually determined.

Durability 1 (scratch resistance): According to JIS K5600-5-6: 1999 "Adhesion (cross-cut method)", when the printed wood grain image part or gradation image part is scratched with a cutter, I evaluated how it looked.
Durability 2 (water scratch resistance): The printed wood grain image portion or gradation image was rubbed by reciprocating a wet cotton swab (load of about 100 g), and the presence or absence of peeling of the image was evaluated.
Hygroscopicity: JIS Z2101: 2012 "Hygroscopicity test" was performed on decorated wood and undecorated wood. The test conditions were a temperature of 40 ° C. and a relative humidity of 90%, and the moisture absorption of the decorated wood and the undecorated wood after 24 hours was compared and evaluated.
The above results are summarized in Table 3.

As shown in the examples, in the surface-treated product using the surface-treated liquid of the present embodiment, the base pattern (wood grain pattern in the case of wood) on the surface of the base material was maintained as it was. On the other hand, in Comparative Example 5 in which the surface treatment liquid 5 using the nonionic water-dispersible resin instead of the cationic water-dispersible resin was used, the surface treatment layer was filmed, so that the surface became too glossy. I couldn't maintain the natural appearance. Further, while a uniform surface treatment layer was formed in the examples, in Comparative Example 9 using the surface treatment liquid 9 containing no surfactant, the surface treatment liquid layer was unevenly adhered to the surface treatment liquid layer. As a result, an unnatural luster was generated.
Further, yellowing and whitening were not observed in any of the surface-treated layers of Examples, but yellowing was observed in the surface-treated layer in Comparative Example 8 using the surface-treating liquid 8 containing the polyvalent metal salt. rice field.

As for the decorative products, in the examples, the image quality was at the passing level and the scratch resistance was also excellent. It was also found that the water-scratch resistance of the image was improved by using the ink containing the water-dispersible resin (Examples 1 to 20 and 23). On the other hand, in Comparative Example 1 and Comparative Example 11 in which the image was formed without surface treatment, a significant decrease in image quality was observed. In Comparative Example 4 in which UV ink was used instead of water-based ink, a cured layer of UV ink was formed on the surface of the wood, so that an unnatural luster appeared and hygroscopicity could not be maintained. It was also found that the scratches on the surface were conspicuous because they did not penetrate inside. Further, in Comparative Examples 5 to 8 and 10 using the surface treatment liquids 5 to 8 and 10 containing no large particles, the fine line reproducibility was particularly lowered, the quality of the printed image was lowered, and Comparative Example 5 shows. As you can see, it was found that even if the image reproducibility is excellent, the surface becomes too glossy and the natural appearance of the decorative part cannot be maintained.

Claims (9)

Contains water, cationic water-dispersible resin, and surface tension modifier,
The cationic is a water-dispersible resin, a median diameter measured by dynamic light scattering method include a 10μm less large particles above 1 [mu] m, wood for surface treatment liquid. The cationic water-dispersible resin, further, the median diameter measured by dynamic light scattering method comprising the small particles of less than 1 [mu] m, according to claim 1 timber for surface treatment solution according. Contains water, cationic water-dispersible resin, and surface tension modifier,
The cationic water-dispersible resin includes large particles having a median diameter of 1 μm or more and 10 μm or less measured by a dynamic light scattering method, and small particles having a median diameter of less than 1 μm measured by a dynamic light scattering method. , a deposition type plate surface treatment solution for,
The molded plate, wooden board, or straw, chaff, and those using a plant-derived material other than wood selected from the group consisting of rushes, adult-type plate surface treatment solution for. Is formed with claim 1 or 2 timber surface treatment solution according, comprising a surface treatment layer comprising at 0.5 g / m ² or more amount of surface treatment liquid solids, surface treated wood. It is formed using a deposition type plate surface treatment solution for according to claim 3, comprising a surface treatment layer comprising at 0.5 g / m ² or more amount of surface treatment liquid solids, a surface treatment molded plate The molded board is a surface-treated molded board using a wood board or a plant-derived product other than wood selected from the group consisting of straw, fir tree, and igusa. Is formed with claim 1 or 2 timber surface treatment solution according, and a surface treatment layer comprising at 0.5 g / m ² or more amount of surface treatment liquid solids, on the surface treatment layer Decorative wood with a formed inkjet printing layer. With formation type plate surface treatment solution according to claim 3, wherein is formed, and the surface treatment layer in an amount of 0.5 g / m ² or more surface treatment liquid solids, formed on the surface treatment layer A decorative molded plate provided with an inkjet printing layer, wherein the molded plate uses a wood board or a plant-derived material other than wood selected from the group consisting of straw, fir tree, and igusa. There is a decorative molding board. A method of manufacturing a decorative wood used claim 1 or 2 timber surface treatment solution according,
Step of forming the wood material for surface treatment solution is applied to the wood surface, the surface treatment layer comprising at 0.5 g / m ² or more amount of surface treatment liquid solids and,
A method for producing decorative wood, which comprises a step of performing inkjet printing using a water-based inkjet ink on the surface treatment layer. A method of manufacturing a decorative molded plate using a forming mold plate surface treatment solution for according to claim 3,
By applying a pre KiNaru type plate surface treatment solution for the molding plate surface, the step of forming a surface treatment layer comprising at 0.5 g / m ² or more amount of surface treatment liquid solids and,
A step of performing inkjet printing using a water-based inkjet ink on the surface treatment layer is included.
The molded board is a method for producing a decorative molded board, which is a wood board or a plant-derived product other than wood selected from the group consisting of straw, rice husk, and rush.